NORHA, A Novel Follicular Atresia-related Lncrna, Promotes Granulosa Cell Apoptosis via miR-183-96-182 Cluster and FoxO1 Axis

Abstract BackgroundFollicular atresia has been shown to be strongly associated with low follicle utilization rate and female infertility, which are regulated by many factors such as miroRNAs (miRNAs), a class of non-coding RNAs (ncRNAs). However, little is known about long non-coding RNAs (lncRNAs), another ncRNAs, which regulate follicular atresia. ResultsA total of 94 differentially expressed lncRNAs, including 74 up-regulated and 20 down-regulated lncRNAs, were identified in early atretic follicles compared to healthy follicles by RNA-sequencing. We identified and characterized a non-coding RNA that was highly expressed in atretic follicles (NORHA), an intergenic lncRNA, was the most significantly elevated lncRNA in early atretic follicles. Functionally, RT-PCR，flow cytometry and western blot results showed that NORHA was associated with follicular atresia by influencing GC apoptosis. Mechanistically, bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay results showed that NORHA acted as a ‘sponge’, which directly bound to the miR-183-96-182 cluster, and therefore resisted their targeting inhibition of FoxO1, the major sensor and effector of oxidative stress. Furthermore, NORHA and oxidative stress synergistically induced GC apoptosis. ConclusionsWe provide a comprehensive perspective of lncRNAs regulation of follicular atresia, and demonstrate that NORHA, a novel lncRNA related to follicular atresia, induces GC apoptosis through affecting the miR-183-96-182 cluster and Foxo1 axis